The earliest catalogue of Bach’s compositions – admittedly a very rough one – was included in the obituary that Carl Philipp Emanuel Bach and Johann Friedrich Agricola wrote immediately after Bach’s death but did not publish until 1754. It scarcely provides an adequate idea of the extent of Bach’s works, but it shows that nearly everything printed during Bach’s lifetime has survived to the present day: Cantata BWV 71, composed for the Mühlhausen town council election in 1708 (but not its counterpart of 1709); the four parts of the Clavier-Übung; the G.C. Schemelli Hymnbook; the Musical Offering (BWV 1079); the Canonic Variations BWV 769; the Schübler chorales; the Art of Fugue (BWV 1080); and the canons BWV 1074 and 1076. The great majority of Bach’s compositions remained unprinted, and most of those survived. The most serious losses occurred among the cantatas: perhaps more than 100, certainly two cycles of church cantatas and several secular occasional works. The funeral music for Prince Leopold of Köthen (1729) and the St Mark Passion (BWV 247) (1731) are among large-scale vocal works of which only the texts survive. A greater proportion of the music for organ and other keyboard instruments has probably survived than that in any other category. Losses among the orchestral and chamber works are almost impossible to estimate, but may be regarded (on the evidence of existing transcriptions, for example) as substantial.

On the assumption that Bach managed to keep his music together as far as possible during his lifetime, it seems that major losses occurred only on the division of his legacy in 1750, when the manuscripts, especially of the vocal works, were divided between the eldest sons and Bach’s widow. Most of them went to Wilhelm Friedemann Bach, but he, unfortunately, was the least succussful at managing his inheritance; he was compelled for financial reasons to sell them off item by item, and the material is not simply scattered but for the most part lost. Only a few of the items inherited by Johann Christoph Friedrich Bach and Johann Christian Bach, including a printed copy of the Musical Offering (BWV 1079) and the autograph of the organ Prelude and Fugue in B minor BWV 544 (signed with Johann Christian’s nickname ‘Christel’), can be traced. C.P.E. Bach’s and Anna Magdalena Bach’s shares were better preserved. Bach’s widow gave her portion (the parts of the cycle of chorale cantatas) to the Thomasschule while most of C.P.E. Bach’s estate passed through Georg Poelchau’s collection into the Berlin Königliche Bibliothek (later the Preussische Staatsbibliothek and now the Staatsbibliothek zu Berlin). This collection forms the basis of the most important collection of Bach archives. During the 19th century this library acquired further, smaller Bach collections, notably those from the Singakademie and the estates of Forkel, Franz Hauser and Count Voss-Buch (in some of which fragments from W.F. Bach’s inheritance appear).

Besides the original manuscripts – the autograph scores, and parts prepared for performances under Bach’s direction – which, in their essentials, Bach kept by him, many copies were made in the circle of his pupils, particularly of organ and harpsichord music. As many autographs of the keyboard works are lost, this strand is specially significant for the preservation of Bach’s works. In particular, important copies have come down through members of Bach’s family (including the Möllersche Handschrift and the Andreas-Bach-Buch, both compiled by Sebastian’s brother Johann Christoph Bach), through Johann Gottfried Walther and through Bach’s pupils Johann Ludwig Krebs and Johann Christian Kittel. After Bach’s death Breitkopf in Leipzig became a centre for the dissemination of his music (again, primarily the keyboard music). In Berlin a notable Bach collection was made for Princess Anna Amalia of Prussia, under the direction of Johann Philipp Kirnberger, in which all facets of Bach’s creative output were represented (now D-Bsb Amalien-Bibliothek). These secondary sources have to serve when autograph material is not available – relatively often with the instrumental works (e.g. a large percentage of the organ pieces; the English and French Suites, toccatas, fantasias and fugues for harpsichord; duo and trio sonatas; concertos and orchestral works), more rarely with the vocal ones (e.g. Cantatas BWV 106 and BWV 159; motets BWV 227-230; and the masses BWV 233 and BWV 235).

Research into source materials, notably in conjunction with the Neue Bach-Ausgabe, has proved fruitful. The use of diplomatic research methods has allowed most of the copyists who worked for Bach – and all the important ones – to be identified: ‘Hauptkopist A’ was Johann Andreas Kuhnau (b 1703); ‘Hauptkopist B’ was Christian Gottlob Meißner (1707-1760); ‘Hauptkopist C’ was Johann Heinrich Bach (1707-1783); ‘Hauptkopist D’ was S.G. Heder (b 1713); ‘Hauptkopist E’ was J.G. Haupt (b 1714); ‘Hauptkopist F’ was Johann Ludwig Dietel (1715-1773); ‘Hauptkopist G’ was Rudolph Straube (b 1717); and ‘Hauptkopist H’ was Johann Nathanael Bammler (1722-1784). Papers, inks and binding have been evaluated for the purposes of identification and dating; but above all Bach’s own handwriting, in its various stages of development, has served as the criterion for dating. A far-reaching revision of the chronology of Bach’s works (only some 40 of the origiare dated) has been made possible, leading to a substantial revision of previous conceptions, which were based for the most part on Spitta’s work. The new chronology was established in its important details by Dürr and Dadelsen during the 1950s. Since then it has been variously added to, modified and confirmed. For the vocal works it is now essentially complete; sometimes it is precise to the actual day. With the instrumental works the situation is more complicated, because the original manuscripts are often lost; in consequence, results have been less precise since the history of the secondary sources permits of only vague conclusions about composition dates (for example, copies originating from the circle around Krebs and J.G. Walther point to a date in the Weimar period); this makes it unlikely that any complete and exact chronology will be established for the instrumental works, though a relative one is now largely achieved.

Investigations of source material have also led to the solution of crucial questions of authenticity, particularly in connection with the early works but also affecting some of the later ones. For example, Cantata BWV 15, hitherto regarded as Bach’s earliest cantata, has now been identified as by Johann Ludwig Bach; similarly, Cantatas BWV 53, BWV 189 and BWV 142 have been excised from the list of his works. Some instrumental works, such as BWV 835-838, BWV 969-970, BWV 1024 and BWV 1036-1037, have been assigned to other composers. On the other hand, an important early organ work, BWV 739, has now been authenticated and its manuscript ranks as probably Bach’s earliest extant musical autograph. Completely new finds have been made (BWV 1081-1120 and BWV Anh.205) and numerous copies by Bach of other composers’ works have come to light; these provide additional information about his repertory and its context.

Bach’s output, unparalleled in its encyclopedic character, embraces practically every musical form of his time except opera. The accepted genres were significantly added to by Bach (notably with the harpsichord concerto and chamber music with obbligato keyboard); further, he opened up new dimensions in virtually every department of creative work to which he turned, in format, density and musical quality, and also in technical demands (works such as the St Matthew Passion (BWV 244) and the B minor Mass (BWV 232) were to remain unique in the history of music for a long time to come). At the same time Bach’s creative production was inextricably bound up with the external factors of his places of work and his employers, as was normal in his time. The composition dates of the various repertories thus reflect Bach’s priorities in his various professional appointments; for instance, most of the organ works were composed while he was active as an organist at Arnstadt, Mühlhausen and Weimar, whereas most of the vocal works belong to the period of his Kantorate at Leipzig. But Bach’s production was by no means wholly dependent on the duties attaching to his office at the time. Thus during his Leipzig period he found time to produce a body of keyboard and chamber music to meet his requirements for concerts, for advertisement, for teaching and other purposes. And his career may be seen as a steady and logical process of development: from organist to Konzertmeister, then to Kapellmeister, and finally to Kantor and director of music – a continual expansion of the scope of his work and responsibilities. This is no matter of chance. Bach chose his appointments, and chose the moment to make each move. If he was unable to accomplish what he required (as was often the case in Leipzig), he was capable of turning his attention elsewhere in pursuit of his creative aims. Bach was a surprisingly emancipated and self-confident artist for his time.

The uncertainty about the dating of Bach’s early works, with so little help in the form of source materials, makes it difficult to reconstruct and assess the beginnings of his work as a composer. It is to be supposed that he started to compose while under the tutelage of his elder brother in Ohrdruf, but although he took no formal lessons with an established composer, as George Frideric Handel did with Friedrich Wilhelm Zachow, it would be mistaken to call him self-taught as a composer, for the significance of his belonging to a long-standing family of professional musicians should not be underestimated. Composing was probably overshadowed by instrumental playing in Ambrosius Bach’s family; this must to some extent have applied to the young Johann Sebastian, and probably he devoted more attention to developing his skills as an instrumentalist, especially as an organist, than to composition studies. But the art of improvisation – in those days inseparably bound up with practice on the instrument – would at the very least prepare the ground for his work as a composer. This reciprocity between performing and composing is reflected in the unruly virtuoso and improvisatory elements in Bach’s early works.

Curiously, C.P.E. Bach’s list of the masters his father had ‘loved and studied’ contains no mention of Antonio Vivaldi and the two Marcellos (Alessandro Marcello & Benedetto Marcello), or of Arcangelo Corelli, Giuseppe Torelli and other late Baroque Italian composers. Forkel compensated for this by his emphasis on the importance of A. Vivaldi’s concertos, without citing any particular source to support his claim. Indeed, it was A. Vivaldi who exercised what was probably the most lasting and distinctive influence on Bach from about 1712-1713, when a wide range of the Italian repertory became available to the Weimar court orchestra. Bach drew from A. Vivaldi his clear melodic contours, the sharp outlines of his outer parts, his motoric and rhythmic conciseness, his unified motivic treatment and his clearly articulated modulation schemes. His confrontation with A. Vivaldi’s music in 1713-1714 provoked what was certainly the strongest single development towards his own personal style. In Forkel's words, A. Vivaldi ‘taught him to think musically’; his musical language acquired its enduring quality and unmistakable identity through his coupling of italianisms with complex counterpoint, marked by busy interweavings of the inner voices as well as harmonic refinement. It is impossible to describe Bach’s personal style by means of simple formulae; but the process of adaptation and mutation that can be felt throughout his output seems to have taken a particularly characteristic turn at that point in 1713-1714 whose principal landmarks are the Orgel-Büchlein and the first Weimar series of cantatas. His adaptation and integration of various contemporary and retrospective styles represent his systematic attempt at shaping and perfecting his personal musical language (‘unlike that of any other composer’, according to C.P.E. Bach) and expanding its structural possibilities and its expressive powers.

An essential component of Bach’s style can be seen in his combination of solid compositional craftsmanship with instrumental and vocal virtuosity. The technical demands made by his music reflect his own prowess as an instrumentalist. Bach’s own versatility – his early involvement in singing (it is not known whether he was later active as a singer), and his experience as a keyboard player, violinist and viola player – was partly responsible for the fact that demanding technical standards became the norm for every type of composition he wrote. This led to Scheibe’s famous criticism: ‘Since he judges according to his own fingers, his pieces are extremely difficult to play; for he demands that singers and instrumentalists should be able to do with their throats and instruments whatever he can play on the keyboard. But this is impossible’. It makes no essential difference at what level these demands are made (for instance between the Inventions and the Goldberg Variations (BWV 988), the four-part chorale and the choral fugue); everywhere Bach’s requirements are the antithesis of conventional simplicity. Yet technical virtuosity never predominates; it becomes a functional element within the composition as a whole. Bach’s impulse towards integration is also manifested in the typically instrumental idiom in which he cast his vocal parts. He thus produced in his music for voices and instruments a homogeneous language of considerable density. Even so, he differentiated between instrumentally and (less often) vocally dominated types of writing; but even in such vocally dominated pieces as the Credo of the B minor Mass (BWV 232) he maintained both the density and the uncompromising, yet appropriate technical standard. It is of course significant, as regards both matters of technique and the quality of his music in general, that, as far as we know, he wrote almost exclusively for himself, his own ensembles and his own pupils, and never for a broader public (let alone a non-professional one). This partly explains why his music – unlike, say, G.P. Telemann’s or G.F. Handel’s – was disseminated within unusually narrow confines.

About two-fifths of Bach’s sacred cantatas must be considered lost; of the secular cantatas, more are lost than survive. Thus it is difficult to draw firm conclusions about the evolution of the cantata in Bach’s hands, even though the surviving repertory is considerable and roughly proportional to the number of cantatas composed at each place where he worked.

The earliest surviving cantatas, and probably Bach’s first, date from the Mühlhausen and perhaps even the Arnstadt period; they include – as the earliest of all – BWV 150, BWV 131, BWV 106 and BWV 196 (c1707). The best, in both form and content, are BWV 106 and BWV 71. The latter is especially sumptuous, and its appearance in print bore the young composer’s reputation far beyond the boundaries of Mühlhausen. The early vocal works belong almost without exception to the category of ‘organist’s music’, that is they are pieces composed for particular occasions, not regular cantatas for the Sundays and feast days in the church calendar. Nor do they conform to the type established as modern by Erdmann Neumeister in 1701, but they rely closely on central German tradition. Their texts are mostly taken from the Bible or the chorale repertory; freely conceived poetry is rare (found only in BWV 71, BWV 106 and BWV 150). Musically they consist of a succession of different formal types – concerto, motet, (strophic) aria and chorale – adapted and combined to suit the composer’s purpose. Bach did not call them cantatas: as a rule he reserved that term for the solo cantata of the Italian type (like BWV 211 and BWV 212), calling his sacred cantatas ‘Concerto’, and in earlier works ‘Motetto’, sometimes ‘Dialogus’ (depending on the text) or simply ‘Music’.

Bach’s early cantatas are distinguished from their central German precursors, which must have been familiar to him from his upbringing, by his tendency to give each movement a unified structure and his development of a broad formal scheme. He found the means to unify movements that for the most part do not function as closed numbers by reducing motivic material (in the solo movements). Reacting against haphazard sequential form, with its danger of formal dissolution, he began to use strictly symmetrical sequences of movements to underpin the overall cyclic structure: for example, chorus–solos–chorus–solos–chorus (no. 106).

During Bach’s early Weimar years, organ music must have dominated his output; on the other hand, the letters written in 1712-1713 by his pupil at Weimar, Johann Philipp Kräuter, show that Bach encouraged him to write cantatas. 1713 is the date, too, of what seems to be Bach’s first secular cantata, the Jagd-KantateBWV 208, written to a commission from the Weißenfels court (where it had a repeat performance before 1717). The piece shows Bach, obviously newly acquainted with the Italian style, taking up the recitative and the modern kind of aria (for preference the da capo aria), a step which had a decisive effect on the next sacred cantatas, BWV 199, BWV 21 and BWV 63 (BWV 21 and BWV 63 were probably written in connection with his application to succeed F.W. Zachow in Halle in December 1713). With his nomination as court Konzertmeister on March 2, 1714, he started to produce cantatas on the whole regularly from the end of March onwards, in accordance with an agreement ‘to perform a piece of his own composition under his own direction, in the chapel of the royal castle, on every fourth Sunday at all seasons’. This was Bach’s first opportunity to compose a whole cantata cycle, albeit over a fairly long time-span; however, as things turned out, the number he wrote in Weimar amounted to little more than 20. The principle of the annual cycle is closely bound up with the history of the cantata from E. Neumeister on; the texts were mostly published in cycles, one for each Sunday and feast day in the church year. Bach, admittedly, never adhered strictly to a single poet (except in the lost Picander cycle of 1728-1729), preferring to pick and choose. In Weimar he turned for the first time to librettos by E. Neumeister (BWV 18 and BWV 61) and used texts by Georg Christian Lehms (1684-1717; BWV 199 and BWV 54), but evidently preferred texts by the Weimar court poet Salomo Franck (1659-1725), the author of extremely original and profoundly felt sacred and secular poetic texts, among the best Bach set. BWV 21, BWV 63 and BWV 199 are among cantatas dating from before 1714; regular production began with Cantata BWV 182 on March 25, 1714. There followed, usually at four-week intervals, in 1714BWV 21, BWV 172, BWV 61, BWV 152; in 1715BWV 18, BWV 54, BWV 31, BWV 165, BWV 185, BWV 163, BWV 132; in 1716BWV 155, BWV 80a, BWV 161, BWV 162, BWV 70a, BWV 186aand BWV 147a. Repeat performances of BWV 21, BWV 199, BWV 31, BWV 165 and BWV 185 were slotted into the cycle. Gaps are accounted for by the loss of certain cantatas and in one case by the period of mourning from August 11, to November 9, 1715.

Musically the works are of particular importance for the development they show in Bach’s personal style of writing for voices and instruments. The recitatives contain extensive arioso sections to begin with, but these gradually disappear (although the combinatorial element was to remain typical of Bach throughout his life); the arias become longer, in free or (more usually) strict da capo form and occasionally using more complex structures. The choruses embrace a multiplicity of formal principles, among them fugue and canon BWV 182), passacaglia (BWV 12), concerto (BWV 172), motet (BWV 21) and French overture (BWV 61). Also notable are the overlapping of instrumental and vocal formal schemes (the use of Chor- and Vokaleinbau) and instrumental quotations of chorale melodies. The extraordinarily colourful instrumentation is especially characteristic: within the smallest of performing ensembles Bach tried out a great variety of combinations, for example recorder, oboe, viola d'amore and viola da gamba in Cantata BWV 152. Following the Italian ideal, his orchestral writing moved away from the French practice of five-part writing, with two violas, which predominates in the early cantatas towards a more flexible four-part style. Instead of the harmonic weight of the middle voices in five-part writing Bach provided a rhythmically and melodically active viola part that is particularly characteristic.

In Köthen, corresponding to Bach’s official responsibilities, only secular cantatas were composed (with the single exception of bwvAnh.5) and those were mostly written for New Year's Day celebrations or the prince’s birthday. Bach’s librettist was Christian Friedrich Hunold (‘Menantes’, 1681-1721). Among the Köthen cantatas, many survive only as verbal texts (Anh.6-8) or are lost altogether; a substantial part of the music survives only for BWV 66a, BWV 134a, BWV 173a, BWV 184a and BWV 194a. These pieces mostly exemplify the ‘serenata’ type of work, with succinct operatic treatment in dialogues between allegorical figures. It is not surprising that they reflect Bach’s study of the instrumental concerto of the period (in part in the solo–tutti differentiation) or that dance characteristics appear, notably in the solo movements. Bach used transverse flutes in Cantata BWV 173a, evidently for the first time.

Thus in his first year at Leipzig Bach furnished himself with an astonishingly concentrated repertory, and his emphasis on the cantata genre also gave him mastery over an incomparable variety of forms, free from any schematicism. Three favourite groundplans are: biblical text–recitative–aria–recitative–aria–chorale (nos.46, 105, 136 etc.); biblical text–recitative–chorale–aria–recitative–aria–chorale (nos.40, 48, 64 etc.); biblical text–aria–chorale–recitative–aria–chorale BWV 86, BWV 144, BWV 166 etc.). A constant feature, characteristic of the Leipzig cantatas as a whole, is the framework, comprising an introductory choral movement in the grand style (solo pieces appear rarely at the start) and closing four-part chorale, simple but expressive. Compared with the Weimar cantatas, the orchestral forces are larger. From BWV 75 onwards the brass (mainly trumpets and horns) are more strongly deployed, the flute is brought into play increasingly after 1724, and the oboe d’amore (from BWV 75) and oboe da caccia (from BWV 167) are introduced as new instruments, as are the violino piccolo and violoncello piccolo at a later date. Instrumental virtuosity is heightened, and the melismatic quality of the vocal writing is further developed. The ‘prelude and fugue’ type of movement is frequently used for the introductory chorus (as in BWV 46).

The second cycle, dating from 1724-1725, consists mainly of a series of freshly composed chorale cantatas (i.e. cantatas of which both text and music are based on hymns): BWV 20, BWV 2, BWV 7, BWV 135, BWV 10, BWV 93, BWV 107, BWV 178, BWV 94, BWV 101, BWV 113, BWV 33, BWV 78, BWV 99, BWV 8, BWV 130, BWV 114, BWV 96, BWV 5, BWV 180, BWV 38, BWV 115, BWV 139, BWV 26, BWV 116, BWV 62, BWV 91, BWV 121, BWV 133, BWV 122, BWV 41, BWV 123, BWV 3, BWV 111, BWV 92, BWV 125, BWV 126, BWV 127 and BWV 1. From Easter 1725 this series was continued at first with cantatas of the traditional kind, that is with texts related to the prescribed scriptural readings for the day (BWV 249, BWV 6, BWV 42 and BWV 85), and then with nine cantatas to texts by Christiane Mariane von Ziegler (1695-1760): BWV 103, BWV 108, BWV 87, BWV 128, BWV 183, BWV 74, BWV 68, BWV 175 and BWV 176, in all of which there is a tendency to use forms closer to those of the first cycle. 1724-1725 was not only the most productive year for cantatas, as far as is known from the surviving works at least; it also, with the chorale cantata, saw the beginnings of a type that perhaps represents Bach’s most important contribution to the history of the genre. What is particularly striking is his endeavour to lay out the introductory movements as large-scale cantus firmus compositions, each adhering to a different structural principle. Cantata BWV 20, and with it the second cycle, opens with a chorale movement for chorus in the form of a French overture which it is possible to regard as a kind of programmatic statement, whereas the opening chorus of BWV 2 takes the retrospective form of a chorale motet. By this means Bach marked out a broad framework, in terms of both musical style and compositional technique, to indicate the conceptual range of the cycle he was starting. Cohesion between the movements within each cantata is guaranteed, at least from the textual point of view, by their relationship to the fundamental chorale (with chorale paraphrases for the solo pieces, as opposed to the procedure in BWV 4); often it is further emphasized by references to the cantus firmus and by the use of various ways of intermingling cantus firmus and free material. The author of the texts for the chorale cantatas is not known – Pastor Christian Weiss of the Thomaskirche, who used to preach chorale sermons, is a possibility.

With the third cycle, from 1725-1727, the continuous, weekly production of cantatas ends, or so the sources indicate. It appears, however, from a surviving printed textbook of 1725 covering the third to the sixth Sunday after Trinity, that this cycle must have suffered substantial losses. When his production was actually interrupted Bach usually filled the gaps with works by other composers, including no fewer than 18 cantatas by his cousin Johann Ludwig Bach of Meiningen. The cantatas of the third cycle offer no major innovations in the way of musical structure, but they notably include solo (BWV 52, BWV 84, BWV 35 etc.) and dialogue cantatas (BWV 58, BWV 32, BWV 49 etc.), as well as large-scale works in two parts. There is an absence of overall formal integrity in the planning of this cycle, but Bach reveals a wide variety of ambitions and intentions, among them completing the cycle of chorale cantatas with further works of that type (BWV 137), reverting to older texts by E. Neumeister (BWV 28), S. Franck (BWV 72), G.C. Lehms (BWV 110, BWV 57, BWV 151, BWV 16, BWV 32, BWV 13, BWV 170 and BWV 35) or from a Rudolstadt textbook (BWV 17, BWV 39, BWV 43, BWV 45, BWV 88, BWV 102 and BWV 187) and experimenting with the use of complementary texts from the Old and New Testaments (the former in the opening movement, the latter in a central one: Rudolstadt texts). One remarkable trait of the cycle is the frequent introduction of older instrumental movements, pre-eminently as sinfonias but sometimes also with choral participation (the reconstruction of the first movement of the Orchestral Suite BWV 1069 to open Cantata BWV 110 is an example of this). A remarkable innovation in summer 1727 was the appearance of obbligato organ parts (BWV 34, BWV 146, BWV 169, BWV 49 and BWV 188), found in both sinfonias (recycling instrumental concertos) and arias.

The third cycle was followed by the 1728-1729 cycle on texts by Picander, which has disappeared but for a few remnants (1728: BWV 149, BWV 188, BWV 197a; 1729: BWV 171, BWV 156, BWV 159, BWV Anh.190, BWV 145 and BWV 174). That Bach really did set the whole of Picander’s Cantaten auf die Sonn- und Fest-Tage durch das gantze Jahr (Leipzig, 1728) as his fourth cycle cannot be accepted without reservation. At the same time, the poet must have been expressing something more than a pious hope when he wrote in the preface ‘that any lack of poetic charm may perhaps be compensated for by the gracefulness of the incomparable Herr Kapellmeister Bach and these songs [Lieder] may be performed in the principal churches of prayerful Leipzig’. One of the characteristics of Picander texts is the frequent interpolation of chorale verses in the free poetry, creating attractive opportunities for mingling choruses and arias, which were not wasted on Bach (see BWV 156 and BWV 159, or the first movement of the St Matthew Passion (BWV 244)). The cantatas written after 1729 offer nothing essentially new in formal terms, as far as can be determined from those that survive, butthey show signs of a late style beginning to develop, manifested (in BWV 195 for example) above all in a more refined shaping of the accompanied recitative and a more integral, polyphonic treatment of the final chorale (entailing some modification of the cantus firmus). Some of the later cantatas (BWV 117, BWV 192, BWV 112, BWV 177, BWV 97 and BWV 100) show an interesting modification of the chorale type: they relinquish freely composed texts but (unlike the older per omnes versustype represented by Cantata BWV 4) set the central movements as recitatives and arias.

It is impossible to reconstruct a fifth cycle worthy of the name from the surviving works (not even given the large number of unattributed four-part chorales), but it would have had to be composed over a rather longer period of time, mainly in the 1730s. The mention in the obituary of ‘five cycles of church pieces, for every Sunday and holy day’ is just a tantalizing hint of how much has been lost.

Besides the cantatas composed in connection with the church year, Bach also wrote sacred cantatas for other occasions, like changes of town council, weddings, funerals, the bicentenary of the Augsburg Confession (1730) and inaugurations of organs; in style these are essentially indistinguishable from the other works. The body of cantatas, for all its variety, has an unusually self-contained character, maintained above all by its consistently high musical quality and its unfailing expressive profundity. The distinctive expressive power of Bach’s musical language did not merely evolve in the cantatas, in many essential respects, but also finds its most characteristic representation in them. His expressive urge, as seen in individual arias and choruses, was not confined to single words as the primary bearers of expression, but was geared to movements and formal sections as a whole, in keeping with Baroque formal models (like the ABA of the da capo aria). Only within the context of a movement’s structural and expressive unity did he regard the special treatment of single words as possible or meaningful. Among the tools of Bach’s craft the traditions of musica poetica and musical rhetoric (the theory of musical figures) must certainly be reckoned. They were deeply rooted in him. Yet to reduce Bach’s intentions to their rhetorical and figural components, or even to emphasize those components, would be to diminish their true breadth. Over and above this objective of expressive unity, Bach was always primarily concerned with the contrapuntal organization of melodic-rhythmic and harmonic textures to establish coherence. That is a principal reason why his cantata movements lend themselves so readily to parody. The technical prerequisites for producing a parody work – which Bach did so often – are metrical similarity and expressive affinity; the most essential requirement, however, is self-sufficiency of the musical substance, and its flexibility leaves considerable scope for the musical interpretation of a new text.

During his early Leipzig years Bach wrote only isolated secular cantatas, but these became more frequent as time passed. They were produced for various occasions: university ceremonies (nos.36b, BWV 198, BWV 205, BWV 207), celebrations at the Thomasschule (BWV Anh.18, BWV Anh.19, BWV 36c), festivities in the houses of noblemen and prominent citizens (BWV 202, BWV 216, BWV 210, BWV 249b, BWV 30a, BWV 210a, BWV 212) and commissions from court (BWV 249a, BWV 36a). Most of his large-scale congratulatory and homage cantatas written for the electoral house of Saxony were produced at the collegium musicum. A favourite format was the operatic dramma per musica, with a simple plot suited to the specific nature of the occasion being celebrated (BWV 213, BWV 206, BWV 214, BWV 207a, BWV 215). The more lyrical cantatas such as BWV 204, or the two Italian works, BWV 203 and BWV 209, would certainly have been performed at the collegium musicum. The Coffee and Peasant Cantatas (BWV 211 and BWV 212), to some extent tinged with folk style, are distinguished by their lifelike and humorous characterization. The librettist of most of the works of 1725-1742 was the versatile Picander, the only other important poet for Bach’s cantatas during this period being Johann Christoph Gottsched (1700-1766), the influential Leipzig professor of rhetoric (BWV 198, BWV Anh.13, BWV Anh.196). There is concrete evidence of just under 40 secular cantatas composed during the Leipzig years, but in most cases only the texts survive. Their occasional nature is the main reason why so many have been lost: few could have been given a second performance, and then only after alterations to the text. Bach was of course aware that their best chance of survival lay in parody, and he took such opportunities as occurred to save the music, as in the case of the Christmas Oratorio (BWV 248).

The three works that Bach called ‘oratorios’ fall within a very short period: the Christmas Oratorio (BWV 248) of 1734-1735, the Easter Oratorio and Ascension Oratorio of 1735. The librettists are not known for certain. The place for Bach’s oratorios in the Lutheran liturgy was the same as that for the cantata; the only difference between the oratorio and cantata texts is that the former have a self-contained ‘plot’ or take the form of narration with dialogue. This conforms with the history of the genre, although Bach held the tendency to formal expansiveness firmly in check, in comparison with standard Italian practice. In the Christmas Oratorio (BWV 248), especially, the normal character of a single self-contained work is contradicted by its being split into sections for six different services between Christmas Day and Epiphany, and this is further emphasized by Bach in his use of different performing forces for the sections (although these are based on an underlying general scheme, and are grouped round six scenes from the Bible, with certain divergences from the allocation of lessons to be read at the various services). The unusual conception of an oratorio performed over several days is reminiscent of the Vincent LübeckAbendmusiken, and the Christmas Oratorio (BWV 248) obviously belongs to the oratorio tradition established by D. Buxtehude. All three of Bach’s oratorios are essentially basedon parodies of secular cantatas whose music, initially associated with a particular occasion, could reasonably be re-used in this way (the Christmas Oratorio (BWV 248) from BWV 213, BWV 214 and BWV 215 among other works; the Easter Oratorio (BWV 249) by a reworking of parts of BWV 249a; the Ascension Oratorio above all from BWV Anh.18). However, there is so much that is new and individual in the Christmas Oratorio (BWV 248), especially in the biblical choruses and the chorales, and in the Ascension Oratorio (BWV 11), that the works are in no sense subordinate to their originals. The pervasive use of texts from the Gospels, moreover, gives the works a special status, linking them to the Protestant historia and thus ultimately to the Passion.

Of the five Passions mentioned in the necrology two survive (St Matthewand St John), for one the text survives (St Mark Passion (BWV 247)) and the other two are lost. Judging from the source it seems probable that the anonymous St Luke Passion – which is certainly not by Bach – was included among his works in error because the score, dating from about 1730, was copied in his hand and contained additions by him. This means that only one Passion remains to be accounted for. Recent research has shown that various movements in the second version of the St John Passion (BWV 245) (1725) were taken from a Passion composed for Weimar, most notably the chorus ‘O Mensch bewein’ and the three arias ‘Himmel, reisse’, ‘Zerschmettert mich’ and ‘Ach windet euch nicht so’. Curiously enough, Hilgenfeldt (1850) mentioned a Passion by Bach dating from 1717, giving no indication of the source of his information, and Bach gave a guest recital at the Gotha court during the Passion period in 1717, making it conceivable that he put on a Passion performance while the post of Kapellmeister was vacant. Also, he performed R. Keiser’s St Mark Passion in Weimar in about 1713, so his interest in the genre is established for the period. The missing fifth Passion must almost certainly, therefore, be a lost Weimar work, but the traces are too few to allow any conclusions to be drawn about it.

The three known works represent the same type of oratorio Passion, in the tradition of the historia, in which the biblical text is retained as a whole (with ‘parts’ for soloists – Evangelist, Jesus, Pilate etc. – and the turba choruses for disciples, high priests etc.), and is interrupted by contemplative, so-called ‘madrigal’ pieces set to freely composed verse, as well as by chorales. A special feature of Bach’s Passions is the unusual frequency of the chorales, which are set in simple yet extremely expressive four-part writing. The text of the St John Passion (BWV 245) of 1724, Bach’s first large-scale vocal work for Leipzig, is not a unified piece of work. The freely composed parts rely heavily on the famous Passion poem by Barthold Heinrich Brockes (Der für die Sünde der Welt gemarterte und sterbende Jesus, 1712) and on texts by C.H. Postel (c1700) and Christian Weise (1675); besides this, the Evangelist’s part contains interpolations from St Matthew’s Gospel. Unlike any other of Bach’s large-scale works, the St John Passion (BWV 245) underwent substantial changes of every kind in the course of its various performances. For the second performance, in 1725, Bach produced a much altered version adapted conceptually to the cycle of chorale cantatas by the incorporation of movements based on a cantus firmus. In a third version (probably of 1732) the interpolations from St Matthew were cut and a new aria and sinfonia added (both lost). Finally a fourth version of 1749 saw the work restored to something much closer to its original form; besides some changes to the text, for his last performance of a Passion in Leipzig Bach greatly enlarged the performing forces (by a part for bassono grosso among other things). It seems that Bach began a thorough-going revision of the work in 1739, but for some reason abandoned the process halfway through movement 10 and did not resume it; furthermore the alterations he made at that time were not adopted in the 1749 performance. For all the modifications made over the 25-year period, the setting of the biblical Passion text remained the work’s constant centre, around which the madrigalian movements in particular were fitted in various ways like different settings for a gemstone. Bach skilfully exploited the network of internal textual correspondences which is unique to St John’s Gospel, and convincingly translated it into an ‘architectural’ structure.

The history of the St Matthew Passion (BWV 244), with its double chorus, is less complicated, though not entirely straightforward. In this case the date of the first performance seems now to be established (the Thomaskirche, Good Friday1727), but some details of that occasion remain unclear because of lacunae in the source material (version bwv244b). Furthermore, some ten movements from the St Matthew Passion (BWV 244) were incorporated into the Köthen funeral music of 1729 (BWV 244a), and the consequences of that for the repeat of the Passion in the same year are not known. On the whole the St Matthew Passion (BWV 244) is a considerably more unified piece than the St John, for which the primary reason is its use of Picander’s text. Its greater textual and musical scale allows more space for the arias and ‘madrigal’ pieces in which the coupling of arioso with aria is an especially characteristic feature. Another special feature is the way the strings provide an accompanying halo in Jesus’s recitatives. The pervading cyclical formation of the work (from the interrelating of the chorales, tonal organization and paired movements) is in some respects even more pronounced than in the St John Passion (BWV 245), while it lacks the earlier work’s ‘architectural’ centre. After 1729 the St Matthew Passion (BWV 244) had at least two more performances under Bach’s direction. In 1736 he made some important changes, chief among them emphasizing the separation of the two choruses and instrumental ensembles by division of the continuo, exchanging the simple chorale at the end of part i for ‘O Mensch bewein’ and replacing the lute in ‘Komm süsses Kreuz’ with bass viol. The additional alterations of about 1742 were mainly a matter of meeting practical performing conditions.

In its main sections, that is in the ‘madrigal’ pieces, the St Mark Passion (BWV 247) of 1731 was a parody work whose main sources are the TrOde (Cantata BWV 198) and the Köthen funeral music (BWV 244a). While only the text survives, the musical design can in part be deduced from these models, although they scarcely permit it to be reconstructed satisfactorily. The Bach literature includes discussion of parody relationships which go further than this, but they seem to raise more questions than they answer. The most plausible suggestion, made by Smend (1940-1948), is that some of the exceptionally large number of chorales in the St Mark Passion (BWV 247) may have survived in the collections of Bach’s four-part chorales.

In Bach’s time Latin polyphonic music was still often used in ordinary Lutheran Sunday worship, particularly, in Leipzig, at important church feasts. Further, the concerted Magnificat continued to hold its place in Vespers. Bach had been interested in Latin polyphonic music at least since his Weimar period, as his copies of pieces by other composers demonstrate (Peranda, Francesco Durante, Johann Christoph Pez, Johann Hugo von Wilderer, Giovanni Battista Bassani, A. Caldara, A. Lotti, G.P.d. Palestrina etc.; catalogue in Wolff, 1968). He also wrote insertions in this style for other composers’ works, and made some arrangements (Sanctus BWV 241; Credo intonation for a mass by G.B. Bassani; ‘Suscepit Israel’ for a Magnificat by A. Caldara). His earliest surviving work of this type is probably the Kyrie BWV 233aon the cantus firmus ‘Christe, du Lamm Gottes’. Then in his first year at Leipzig came the five-part Magnificat, first theE-flat version with four inserted Christmas pieces (BWV 243a), revised in D major in 1733, without the Christmas pieces, for use on any major feast day (BWV 243). Among the various Sanctus settings attributed to Bach, apart from BWV 232III, probably only BWV 237 and BWV 238 (both 1723) are original compositions. The four short masses (BWV 233-236), mostly parody works based on cantata movements, date from about 1738. In the careful selection of models and the subsequent reworking of the musical material, these works, together with the B minor Mass (BWV 232), amount to a valuable anthology of Bach’s vocal writing in music of outstandingly high quality. The transposition of German cantata movements into mass settings did more than replace German words, contingent on the time and occasion of their writing, with the timelessness of the Latin (and Greek) texts; it also removed the limitations imposed on the cantatas by their place in the annual church cycle and gave them a more general validity. The longer-term outcome of this was seen soon after 1750, when specifically the Latin sacred music was hailed by connoisseurs like Marpurg, J.P. Kirnberger, Hiller and even the south German Prince-Abbot Gerbert as a particularly important sector of Bach’s music.

Bach’s masterpiece in this genre is of course the work known – though not conceived as a unity – as the B minor Mass (BWV 232). Its genesis stretched over more than two decades. Bach’s aim seems originally to have been to bring together a collection of exemplary large-scale mass movements rather than to create a single, cyclical work on an unprecedented scale. In assembling the whole score in 1748-1749, however, the composer undoubtedly had the intention of making it a comprehensive work of consistent quality. The oldest section is the Sanctus of 1724. The Kyrie and Gloria come from the 1733Missa dedicated to the Dresden court, while the Credo or ‘Symbolum Nicenum’ was composed only during Bach’s last years. In many respects these two main sections represent Bach’s ideals not of Latin polyphonic music alone but of vocal music altogether: in their stylistic multiplicity (the contrast of deliberately archaic and modern styles; the experimentation with the widest variety of instrumental and vocal techniques); their abandonment of the da capo aria and the recitative; and in their formal perfection. The 1733Missa (reminiscent of the Magnificat in its five-part writing) emerges as a completely integrated, unified whole, typified by the inner logic of the tonal organization (B minor–D–F-sharp minor–D–A–D–G–B minor–D) and the disposition of the vocal and instrumental solos. The Credo is a particularly good example of Bach’s many-layered and symmetrical layout (See: Table 1).

The Missa and the Credo have a series of parody originals (including movements from Cantatas BWV 29, BWV 46, BWV 171, BWV 12 and BWV 120); in the latter the ‘Credo’, ‘Et incarnatus’ and ‘Confiteor’ seem to be the only original compositions.

An earlier version of ‘Credo in unum Deum’ exists, dating from the early 1740s, while ‘Et incarnatus’ may be the last vocal composition that Bach completed. However, Bach’s reworking of earlier material went much further than usual. In ‘Agnus Dei’, in particular, nearly half the movement was completely revised, using new thematic material. When the entire work was nearly finished Bach revised it once more, probably in 1749, adding ‘Et incarnatus’ (the words of which he had originally set as part of the aria ‘Et in unum Dominum’). The music of the new ‘Et incarnatus’ is reminiscent of a movement in Giovanni Battista Pergolesi’s Stabat mater, and in its combination of unorthodox polyphony and musically expressive gesture points the way forward to a new stylistic sensibility. It is all the more astonishing that Bach successfully followed it with the earliest music in the mass, the ‘Crucifixus’ (from the second movement of Cantata BWV 12) – though he did bring this up to date with a more empfindsam style of continuo and more subtle instrumentation of the upper parts.

It was obviously not by chance that Bach turned in his old age to the mass genre. With its centuries-old tradition, by comparison with such modern genres as the cantata and oratorio, the setting of the mass had a natural affinity to the historical and theoretical dimensions of Bach's musical thinking, which also bore fruit in the monothematic instrumental works of his last years.

In Bach’s time motets were sung as introits for services and on certain special occasions. The tradition established at Leipzig was to select introit motets from the Florilegium Portense (1603), a classical repertory from the 16th century compiled by Erhard Bodenschatz. For this reason, Bach wrote motets only for special occasions, probably only for burial services, although in only one case, Der Geihilft (BWV 226) (for the funeral of the Thomasschule headmaster Ernesti in 1729), is there documentary evidence of this. Bach’s motet texts, following the tradition, are based on biblical quotations and chorales; freely composed poetry is used in only one case, and even this is hymnbook poetry (Komm, Jesu, komm (BWV 229), Paul Thymich). On the occasions for which the motets were composed, Bach normally had more than the school choristers at his disposal; he was thus able to use between five- and eight-part writing, as he did in six pieces (BWV 225-229 and BWV Anh 159). In line with normal central German practice since the 17th century, it was a rule in the performance of motets at Leipzig, including those from Florilegium Portense, that a continuo part should be included – to be precise, organ, harpsichord (in Leipzig the so-called motet harpsichord), lute, with violone, cello, bassoon. In this way the bass of a vocal (choral or polychoral) movement was supported by a larger or smaller continuo depending on the circumstances, in the manner of a basso seguente. Colla parte accompaniment was required only occasionally. The performing parts that have survived for Der Geist hilft (BWV 226), with strings (first chorus) and reed instruments (second chorus) doubling the voices, must be connected with the exceptional nature of the occasion and cannot necessarily be taken as applicable to the other motets; similar special cases, with partly obbligato instruments, are BWV 118, O Jesu Christ (both versions) and Motet Der Gerechte kömmt um (not in BWV: BC C 8).

Bach’s use of double chorus and his exposition of forms of chorale treatment link the motets with the central German tradition in which he had grown up. That it was part of his direct family inheritance is illustrated by the fact, which can scarcely be coincidental, that motets are particularly well represented in the Alt-Bachisches Archiv. Bach’s earliest motet, Ich lasse dich nicht bwv BWV Anh 159, long attributed to Johann Christoph Bach of Eisenach, adheres extremely closely to Thuringian models. Composed by 1712 at the latest, the work’s foundations in the tradition are typified by the highlighting of upper parts and the largely homophonic conception of the first section, and by the interweaving of a chorale tune in large note values in the second; by contrast, the harmonic intensity of the work (in F minor) and the unified, almost rondo-like, thematic construction of its first section are innovatory. Among later works, Bach’s debt to the tradition is best illustrated by the closing section of Fürchte dich nicht (BWV 228), in its combination of cantus firmus (‘Warum sollt ich mich denn grämen’) and freely imitative writing, and the opening section of Komm, Jesu, komm (BWV 229), with its chordal writing for double chorus. As a whole, the style of BWV 118 too is retrospective, with its archaic instrumentation and its homophonic choral writing.

By contrast, most movements in the motets have a markedly polyphonic vocal manner, dominated by instrumental style and showing unifying motivic work. Another characteristic is the clear formal articulation, with multi-movement works demonstrating different kinds of treatment. Thus Jesu, meine Freude (BWV 227), the longest work of this kind, in 11 movements, is the most strictly (that is, symmetrically) conceived: the opening and closing movements are identical, the second to fifth correspond to the seventh and eighth, and the central sixth movement is a fugue. Der Geist hilft (BWV 226) begins with a concerto-like movement, followed by a double fugue and a simple chorale setting. The form of the instrumental concerto (fast–slow–fast) is used in Singet dem Herrn (BWV 225). Precise dating is possible only in the case of Der Geist hilft (BWV 226) (October 24, 1729). Jesu meine Freude seems to date from a pre-Leipzig period, although there is no tangible evidence for this; it is possible that an earlier motet, with a text from Romans viii, was expanded into a chorale motet by the addition of stanzas from the hymn Jesu meine Freude. The other motets appear to date from the Leipzig years. This is certain in the case of O Jesu Christ (c1737): its instrumentation was revised for a repeat performance in the 1740s, with strings, oboes, bassoons and horns; the original had only two litui, cornets and three trombones. The authenticity of Lobet den Herrn (BWV 230) has been questioned, probably groundlessly, but the paucity of material that would permit comparisons weakens the arguments on either side. Bach’s arrangement of G.B. Pergolesi’s Stabat mater with the psalm text ‘Tilge, Höchster, meine Sünden’ (BWV 1083), dating from 1741-1746, should be counted among the motets.

Bach’s composition of chorales is most closely associated with his production of cantatas. Four-part chorale style, or stylus simplex, was normal for his closing movements, particularly in the Leipzig cantatas; it also often occurred at the ends of subsections in the Passions and oratorios. Bach’s chorale writing is characterized by the ‘speaking’ quality of the part-writing and the harmonies – meaning that they aim to be a direct interpretation of the text. In its pervasive counterpoint and its expressiveness, Bach’s harmonic style stands out from that of his contemporaries, who preferred plain homophonic textures in their chorales. This simpler approach, found in the chorales of such as Christoph Graupner or G.P. Telemann, with movement mostly in minims, was well suited to congregational singing, but Bach took no account of that in his chorales, which are deliberately more artistic, rhythmically often more lively (written in crotchets) and frequently bolder in their harmonies. The first four-part chorale settings are in the Weimar cantatas (the last movement of BWV 12, performed on April 22, 1714, is among the earliest examples), and Bach’s stylistic development in this type of composition reached a final stage 30 years later in the chorales of the Christmas Oratorio (BWV 248), with their elegantly mobile bass lines and their polyphonic refinement of the inner voices. His training as an organist probably contributed to the personal stamp of his style; organ settings such as bwv706 display similar stylistic traits. Chorales such as BWV 371, conceived with orchestral forces in mind, act furthermore as reminders that chorales were Bach’s favourite medium of instruction. C.P.E. Bach wrote in 1775: ‘His pupils had to begin by learning four-part thoroughbass. After that he went on with them to chorales; first he used to write the bass himself, then they had to invent the alto and tenor for themselves … this way of leading up to chorales indisputably the best way of learning composition, including harmony’.

The posthumously published collections (Birnstiel, 2 vols., 1765, 1769; Breitkopf, 4 vols., 1784-1787) contain almost all the chorales known from Bach’s vocal works, some under different titles. The Breitkopf edition, prepared by C.P.E. Bach and J.P. Kirnberger, contains 371 chorales, among them more than 100 not found in the extant vocal works. This provides an important pointer to the lost vocal music, and though extremely difficult to follow up it has borne some fruits, as in the reconstruction of the St Mark Passion (BWV 247) or the Picander cycle. It is worth remarking that the number of excess chorales, that is those that cannot be assigned to extant works, more or less corresponds to the number thought to exist in the lost cantatas and Passions.

Under the generic heading of ‘sacred songs’ come the 69 melodies with figured bass in Georg Christian Schemelli’s Musicalisches Gesang-Buch (1736). According to the foreword, Bach edited the figured bass for some of the melodies, while others were entirely new compositions by him. Three are demonstrably his (BWV BWV 452, BWV 500 and BWV 505); of the rest at least seven pieces for two voices and ten ‘improved’ continuo parts can be associated with him. He seems to have been only peripherally occupied with the composition of songs and strophic arias, for which he took texts from religious poetry of the 17th and 18th centuries: that, at least, is the inference to be drawn from the limited surviving repertory, for which the only source is the second Clavierbüchlein for Anna Magdalena Bach (1725) containing BWV 511-514 and BWV 516 – works which probably have a direct association with the G.C. SchemelliGesangbuch. Comparison of BWV BWV 512 with 315, and of BWV BWV 452 with 299, draws attention to the conceptual association between the composition of chorales for two and for four voices. The collection of four-part chorales which Bach’s pupil J,L. Dietel extracted from his teacher’s works (Leipzig, c1735), like the G.C. SchemelliGesangbuch (1736), indicates that Bach was working on chorales rather intensively and systematically at the time, perhaps with a view to a more compendious publication.

Only exceptionally did Bach compose secular songs. A quodlibet for four voices and continuo (BWV 542), surviving only in fragmentary form, is unique among his vocal works. It was probably composed for a wedding in Erfurt, at the latest by mid-1708. With its admixture of various melodies and humorous words, the piece forms a link with the musical games played, so tradition relates, when the Bach family got together. Other rarities, from a later period when he was settled in the university town of Leipzig, are the song addressing a pipe of tobacco (BWV 515) and the ‘Murky’ (BWV Anh.40).

The obituary written immediately after Bach’s death and published in 1754 contains the following statement: ‘For as long as there is nought to confute us other than the mere possibility of the existence of better organists and keyboard players, we cannot be reproached if we are bold enough to persist in the claim that our Bach was the most prodigious organist and keyboard player that there has ever been. It may be that this or that famous man has accomplished much in polyphony on these instruments but was he for that reason as expert – with hands and feet together – as Bach was? Whosoever had the pleasure of hearing him and others, being not otherwise disposed by prejudice, will agree that this doubt is not unfounded. And whosoever looks at Bach’s pieces for the organ and the keyboard, which he himself, as is universally known, performed with the greatest perfection, will likewise have nothing to say in contradiction of the above statement.’ The claim illustrates the well-nigh legendary reputation that Bach enjoyed in his lifetime. His fame had already spread beyond the confines of central Germany by 1717, when he challenged the French virtuoso Louis Marchand to a competition at the court of Dresden and won by default when the Frenchman took flight. ‘It would be wrong to conclude from this defeat of Marchand in Dresden that he must have been a poor musician. Did not as great a one as G.F. Handel avoid every opportunity of confronting the late Bach … or of getting involved with him?’ (Marpurg).

Keyboard music as a whole occupies a crucial position in Bach’s life in many respects, but this is even more true of the works for harpsichord than of those for organ. No other genre occupied Bach so consistently and intensively from the beginning of his career to the end. His life as a professional musician began with learning to play on a keyboard, above all in Ohrdruf in 1695-1700 under the tuition of his elder brother Johann Christoph Bach, and his study of keyboard music by the best composers of the 17th century laid the most important foundations of his training as a composer. The compositions for harpsichord, in particular, provide the opportunity to assess Bach’s development at each stage of his creative life.

Bach was bolder than any of his contemporaries: from the first he set no limits to his keyboard skills, and accepted no restrictions to his horizons – from the breadth of the foundations of his style to the comprehensive range of genres in which he composed. The stylistic basis was laid in his youth, and it was undoubtedly important that growing up in the central German environment of his time gave him the opportunity to learn about different stylistic tendencies side by side, without any bias towards one rather than another. As a result his models came from a highly diverse repertory. The north German school, including such masters as D. Buxtehude, J.A. Reincken, N. Bruhns, V. Lübeck and G. Böhm, were ranged alongside central German composers such as J. Pachelbel’s circle and older pupils (Johann Heinrich Buttstett, for example, or Nicolaus Vetter) and Christian Friedrich Witt, Johann Krieger, Johann Kuhnau and F.W. Zachow, as well as their southern German colleagues J.J. Froberger, J.K. Kerll and J.C.F. Fischer. Italians such as G. Frescobaldi and Battiferri confronted Frenchmen such as Lully, Marais, Nicolas de Grigny and André Raison. Many of these names are to be found in the large manuscript collections (the so-called Andreas-Bach-Buch and Möllersche Handschrift) copied by the Ohrdruf Bach, Johann Christoph Bach. They give a clear picture of the repertory that the younger brother grew up with, and which showed him – like the young G.F. Handel, learning his craft in a similar environment – ‘the manifold ways of writing and composing of various races, together with each single composer’s strengths and weaknesses’. No comparable sphere of influence served to challenge this broadly based group of musicians and exemplars later in Bach’s life. There were, of course, individuals who had an effect on him, such as A. Vivaldi after 1710, or probably François Couperin, or his exact contemporary G.F. Handel, but no group of musicians of a comparable range or variety.

Bach’s dedication to every keyboard genre and form appears equally boundless. The range remains constant throughout his career, from the earliest to the last compositions. All the major types are represented: the freely improvisatory (prelude, toccata, fantasia), the imitative and strict (fugue, fantasia, ricercar, canzona, capriccio, invention), the combinatory (multi-part preludes, prelude and fugue) and multi-movement forms (sonata, suite or partita, overture or sinfonia, chaconne or passacaglia, pastorale, concerto and variations); and then there are the various types and forms of chorale arrangement.

Unlike the vocal music and the chamber and orchestral works, Bach’s keyboard output covers his entire creative life. There are quite lengthy periods of heightened activity – organ music before 1717, harpsichord music after that date. As a whole, however, Bach seems to have cultivated the two genres alongside each other. It is thus the more surprising that, right from the beginning, consistently and in defiance of inherited 17th-century tradition, he abandoned the conventional community of repertory between organ and harpsichord, choosing to write specifically for the one or the other. The uncompromising use of obbligato pedals, in particular, is a distinguishing mark of Bach’s organ style. Only exceptionally (for example in the chorale partitas and the small chorale arrangements from the third part of the Clavier-Übung) do the performing possibilities coincide so that organ and harpsichord become truly interchangeable.

Since most of Bach’s keyboard works from the pre-Leipzig years survive in copies (generally made in the circle of Bach’s pupils) rather than in autograph scores, it is not possible to establish a precise chronology. Even a relative one is possible only in general terms, with considerations of style and authenticity holding the balance. In the earliest works the influence of Bach’s models is pronounced. J. Pachelbel had taught Johann Christoph Bach, and the master’s influence extended to the younger brother, most visibly and prevalently in the earliest of his extant compositions. Besides the little organ chorales which survive individually (BWV 749, 750 and 756), regarded by Spitta as Bach’s first musical essays, the chorales in the E. Neumeister collection, which came to light only recently (BWV 1090–1120, and BWV 714, 719, 737, 742 and 756), are now taken to be among his earliest works. Although the E. Neumeister manuscript represents neither an integrated body of work nor a unified collection, in its dazzling variety it embodies some contradictory and simultaneously essential traits of Bach’s early organ music: imperfect technique alongside daring innovation; reliance on models such as J. Pachelbel, Johann Michael Bach and Johann Christoph Bach and masters from north, south and central Germany, together with a determination to surpass and dispense with such models; and an entirely unorthodox mixture of free composition and strict polyphony, unconventional harmony and pronounced virtuosity.

A subsequent stage in Bach’s development is found in the chorale partitas BWV 766-768, mostly wrought in the manner of G. Böhm (BWV 768 was revised and expanded during Bach’s Weimar period). The Canzona bwv588, the Allabreve BWV 589 and the Pastorale bwv590 show south German and Italian characteristics, while the Fantasia in G BWV 572 looks to the French style. With their sectional layout, the preludes in E and G minor, BWV 566 and 535a, must have been written under D. Buxtehude’s immediate influence.

The extraordinary harmonic boldness and the richness of fermata embellishment in the pieces BWV 715, 722 and 732, intended to accompany chorales, imply that they belong to the Arnstadt period when Bach’s treatment of chorales caused confusion among the congregation. The fugues after Giovanni Legrenzi and Arcangelo Corelli, BWV 574 and 579, should probably be placed among the early works. Admittedly, the scarcity of autographs, combined with the complicated situation surrounding the other sources, makes it difficult to establish a reliable chronology. It is scarcely possible even to draw definite conclusions about which of the early keyboard works belong within the period of Bach’s youth, if that is set at about 1700-1707.

The models recede in importance from the Mühlhausen period, at the latest, and Bach’s individuality begins to pervade every note of his compositions. This applies particularly to the many extended organ chorale settings probably dating from between 1709 and 1712–1713 and already so much in accordance with Bach’s later ideals that he found this group of 18 chorales (bwv651–8) worthy of revising in and after about 1740. In his freely composed organ works (toccatas, preludes, fantasias and fugues) Bach tightened up the formal scheme, preparing the way for the two-movement prelude and fugue through an intermediate type in which the fugue was a long, self-contained complex but the prelude was not yet a unified section (such as the first movement of BWV 532). Here is an early manifestation of one of the peculiarities of Bach’s working methods, encountered later in the ‘48’: fugues attain their final form almost instantaneously, preludes often go through several stages of development. Probably the most important work of these years is the Passacaglia in C minor BWV 582.

In about 1713-1714 a decisive stylistic change came about, stimulated by A. Vivaldi’s concerto form. Bach’s encounter with A. Vivaldi’s music found immediate expression in the concertos after A. Vivaldi’s opp.3 and 7 (bwv593 etc.). Features adapted from A. Vivaldi include the unifying use of motivic work, the motoric rhythmic character, the modulation schemes and the principle of solo–tutti contrast as means of formal articulation; the influence may be seen in the Toccatas in F and C BWV 540 and 564. Apparently Bach experimented for a short while with a free, concerto-like organ formin three movements (fast–slow–fast: cf BWV 545 + 529/2 and BWV 541 + 528/3) but finally turned to the two-movement form, as in BWV 534 and 536. Of comparable importance to the introduction of the concerto element is his tendency towards condensed motivic work, as in theOrgel-Büchlein. Bach’s conception of this new type of miniature organ chorale, combining rhetorical and expressive musical language with refined counterpoint, probably dates back to a relatively early point, possibly the beginning of the Weimar period, but he cannot have started to collect them systematically in the autograph before 1713-1714. Among the earliest entered in the manuscript are, among new compositions, BWV 608, 627 and 630, and around 1715-1716 Bach added BWV 615, 623, 640 and 644 (to cite some typical examples). Some of the pieces, such as BWV 601 and 639, are of earlier date. By the end of the Weimar period the Orgel-Büchleinwas complete in all essentials, although a few isolated pieces were added later, such as BWV 620 and 631 (c1730), the fragment O Traurigkeitand bwv613 (c1740). The final total of 45 pieces falls considerably short of the 164 originally projected, but Bach had already ceased to work consistently at this major undertaking as early as 1716. The reason for this is unknown; when he took it up again in Leipzig it was only sporadically and apparently in connection with teaching, or so a copy made about 1727-1730 suggests.

Bach composed few organ pieces at Köthen, but among them is undoubtedly the C major Fantasia BWV 573 which he added to Anna Magdalena Bach’sClavier-Büchlein (1722). In Leipzig, in about 1727, he composed the trio sonatas, a new genre for the organ, which he wrote, according to Forkel, for his eldest son W.F. Bach. It was probably in conjunction with renewed activity as a recitalist – he is known to have performed in Dresden (1725, 1731 and 1736), Kassel (1732), Altenburg (1739) and Potsdam (1747) – that he returned to the prelude and fugue genre. Now, surely as a consequence of the ‘48’, he always wrote them in two sections, with the preludes as important as the fugues. There was a final flourish of virtuosity (especially in the writing for obbligato pedal) in works such as BWV 544 and 548 (both c1730), but always in the context of a clearcut structure (there is a da capo fugue in BWV 548).

In 1739, as the third part of the Clavier-Übung, Bach published a comprehensive and varied group of organ works. Framed by a Prelude and Fugue in E-flat (BWV 552), there are nine chorale arrangements for Mass and 12 for the catechism, followed by four duets. Bach’s encyclopedic intentions can be seen in the form of the work – that of a collection of specimen organ pieces for large church instruments and smaller domestic ones (including the harpsichord), symbolized in his invariable coupling of a large piece with a small; they can equally be seen in the variety of his contrapuntal methods, whereby he constantly produced fresh kinds of cantus firmus treatment. At the very end of Bach’s output for the organ are such disparate works as the C minor Fantasia and Fugue BWV 562 (1747-1748), the ‘Schübler’ chorales (arrangements after solo movements from cantatas) and the canonic variations on Vom Himmel hoch BWV 769. The variations, written for Mizler’s society in 1747, survive in two original versions, printed and autograph, whose different sequence of movements shows Bach experimenting with symmetrical form and the placing of climaxes

Just as Bach learnt most about the craft of composition from keyboard music, so too did he use it for preference in teaching others. He was obviously already a sought-after teacher when still in Weimar, but the move to Leipzig brought a decisive expansion of his teaching activities. Heinrich Nicolaus Gerber, who studied with him in the early Leipzig years, left an account of Bach’s method of introducing the widest variety of composition by gradual stages, along with the technical premisses of their performance. According to H.N. Gerber he used to begin with the Inventions and the French and English suites, and conclude the course with the ‘48’. This canon of characteristic works from the decade 1715-1725 constitutes, so to speak, the stylistic core of Bach’s music for keyboard and for that reason served later as the yardstick by which to settle questions of authenticity. Nowadays, however, the yardstick’s usefulness has become somewhat problematic, since it does not take fully into account either the stylistic breadth of Bach’s early output or the unorthodox musical language of the late works.

One of the essential elements of Bach’s art as a keyboard composer is the attention he gave, from the first, to the idiomatic qualities of the individual instruments, respecting not only the differences between organ and harpsichord but also those within the family of string keyboard instruments, of which he used at least four types: harpsichord, clavichord, lute-harpsichord and fortepiano. He is specific about the main kinds of harpsichord in the Clavier-Übung(the first part is for one-manual harpsichord, the second and fourth for a two-manual instrument). One of the earliest manuscript sources refers to the suitability of the E minor suite bwv996 for the lute-harpsichord (‘aufs Lauten Werk’). Bach took an active interest in J.G. Silbermann’s experiments in developing the fortepiano during the 1730s and 40s. There is reliable testimony that he improvised on several new Silbermann fortepianos of different types in the presence of Frederick the Great in Potsdam in 1747, which makes it possible to regard the three-part ricercar of the Musical Offering (BWV 1079)as conceived primarily for this new kind of keyboard instrument.

There is an obvious association between Bach’s renown as a keyboard virtuoso, together with his work as a teacher, and the fact that his keyboard music is among the most accessible of his entire output, and also that it was the most widely available. Its dissemination shows a marked rising curve during the 18th century, internationally as well as within Germany. Bach’s harpsichord works were available in Italy, France, Austria and England by 1750, and in view of this it is not surprising that the young Beethoven was schooled in the ‘48’. The growing recognition of the significance of this part of his output was reflected in the first complete edition of the works for harpsichord (begun in Leipzig in 1800 by Hoffmeister & Kühnel and continued by C.F. Peters) in which Forkel, among others, winvolved.

Bach’s early harpsichord compositions are in a similar situation to the early organ works as regards dating and evaluation. None of the very earliest can be dated precisely. The Capriccio BWV 992 has been assigned to 1704; there are no biographical data to support this (it is extremely doubtful that it was written for Bach’s brother Johann Jacob Bach), but it certainly belongs to the period immediately after 1700. Before 1712-1713 there were countless individual pieces like toccatas, preludes and fugues (these last mainly using a ‘repercussive’ thematic technique like the early organ fugues); variation form is represented by the Aria variataBWV 989. In the toccatas (BWV 910 etc.) Italian, north German and French influences conjoin in equal importance (BWV 912 is an interesting counterpart to the organ work BWV 532); Bach’s penchant for the French style is evident in his abundant use of the style brisé. After 1712 the particular influence of concertos by A. Vivaldi, Marcello and others can be seen in Bach’s numerous concerto arrangements (BWV 972 etc.).

To the last years in Weimar and the early years in Köthen belong works such as the so-called English Suites and the Chromatic Fantasia and Fugue BWV 903, and also the Clavier-Büchlein for W.F. Bach of 1720, which is predominantly didactic in layout. It is however less important for its instruction in playing technique (the ApplicatioBWV 994 gives fingering and tables of ornaments after D’Anglebert) than as a book of instruction in composition. For Bach himself, the two could not be dissociated: the Clavier-Büchlein contains the beginnings of the ‘48’ as well as early versions of the Inventions and Sinfonias, under such titles as ‘preambulum’ and ‘fantasia’. To some extent the 1722Clavierbüchlein for Anna Magdalena Bach is a companion work, though differently laid out.

Then followed, also in 1722, Das wohltemperirte Clavier (book 1 of the ‘48’), with its 24 preludes and fugues in all the major and minor keys, surpassing, in logic, in format and in musical quality, all earlier endeavours of the same kind by other masters, such as J.C.F. Fischer’s Ariadne musica. The work shows a perfectly balanced contrast between free and strict styles, each represented by several different types of prelude and fugue. Bach’s writing in book 1 of the ‘48’ in the most varied fugues – from two- to five-part, in a wide range of styles – represents the culmination of a 20-year process of maturation and stands unparalleled in the history of music. The final version of the two- and three-part Inventions and Sinfonias, also arranged by key but representing a different method of composition whose object (according to Bach’s foreword) was ‘to teach clear playing in two and three obbligato parts, good inventions [i.e. compositional ideas] and a cantabile manner of playing’, dates from 1723.

The first traces of the subsequent great works of the Leipzig period are to be found in the 1725Clavierbüchlein for Anna Magdalena Bach, which in fact anticipates the so-called French Suites BWV 812-817 and the Partitas BWV 825-830. The Partitas in particular (appearing in print singly from 1726) represent a further culmination in Bach’s keyboard output; whereas the ‘48’ shows the prelude and fugue type developed to its most consummate maturity, these present similarly matured specimens of the most popular harpsichord genre of the time, the partita, comprising a suite of dance movements and ‘galanteries’. These – the burlesca, capriccio and the like – do not appear in the English or French Suites; as in the English Suites, each partita begins with a large-scale movement, each differently titled and each in a different style. Later, with the collected publication of all six in 1731, Bach inaugurated his series of published works under the general title Clavier-Übung (the title was borrowed from a publication by J. Kuhnau, his predecessor in office). In 1735 appeared the second part, whose contents were intended to be representative of the most prominent and fashionable styles: the Concerto in the Italian Style bwv971 embodies the ultimate stage in the process of transcribing instrumental concertos for keyboard, and stands in contrast to an Overture in the French Manner BWV 831 which, more markedly than the partitas, represents what was specifically French in harmony, rhythm, ornamentation and melodic invention. 1741-1742 eventually saw the end of the Clavier-Übung series with the aria and 30 variations known as the Goldberg Variations (BWV 988). Apparently Bach had not cultivated the variation form since his youth, so that the contrast between the Goldberg Variations (BWV 988) and the early works (chorale partitas and theAria variata) is the more marked. This work outshines all others as far as performing technique is concerned (Domenico Scarlatti’s influence is unmistakable in places). The large-scale cyclical layout (based on a sequence of 10 x 3 movements, incorporating a series of nine canons, one at every third variation, arranged in order of ascending intervals to move towards a climax, with a final quodlibet) is without precedent. The basis of the composition is a ground bass of 32 bars, developed from the Ruggiero and related bass patterns, first presented in the aria and then subjected to free and canonic elaboration in a wide variety of ways. In their monothematic and emphatically contrapuntal conception, the Goldberg Variations (BWV 988) set the scene for Bach’s last keyboard works – the Musical Offering (BWV 1079) and Art of Fugue (BWV 1080).

Besides the harpsichord works published in the 1730s, the only other major work is the second part of Das wohltemperirte Clavier (not so titled – the complete autograph does not survive). This companion-piece is less unified than book 1 and was partly assembled from existing preludes and fugues, some of them transposed. The freshly composed pieces probably date chiefly from the late 1730s; the work was complete by 1744 at the latest. Apart from this one major undertaking, Bach appears to have composed very few keyboard works at this period: perhaps the Fantasia ‘sur un rondeau’ BWV 918, certainly the Fantasia in C minor with fragmentary fugue BWV 906.

The dates of composition of the seven surviving works for lute – apparently almost his total output for the instrument – cover at least 30 years. The earliest work is the Suite in E minor BWV 996, which dates from the Weimar period; it already shows a surprisingly balanced construction. The Prelude in C minor BWV 999 shows an affinity with the ‘48’, and may thus belong to the Köthen or early Leipzig period. All the other lute works were composed in Leipzig, starting with the Fugue in G minor BWV 1000, an expanded polyphonic development from the violin fugue (in BWV 1001), which (like BWV 997) is in a tablature copied by Bach’s friend, the Leipzig lawyer and lutenist Johann Christian Weyrauch. The Suite in G minor BWV 995 (after BWV 1011, for cello) dates from the period 1727-1731 and is dedicated in Bach’s autograph to an unidentifiable ‘Monsieur Schouster’. The Suite in E (BWV 1006a, after BWV 1006 for violin) also survives in autograph form and is a much less demanding arrangement of its model as compared with BWV 1000 and BWV 995; it dates from the second half of the 1730s. Bach must have composed the Suite in C minor BWV 997 before 1741; this is an original lute composition and is laid out in a similar virtuoso fashion to the Prelude, Fugue and Allegro in E-flat BWV 998 which can be ascribed to the early 1740s. The late works may have been written for the Dresden lutenists Silvius Leopold Weiss and Johann Kropffgans, and in any case were probably played by them. There is evidence that S.L. Weiss and Kropffgans performed at Bach’s house at least once, in 1739. Bach’s arrangement for violin and harpsichord of S.L. Weiss’s lute suite in A major (BWV 1025) may have been made in connection with this occasion. His contributions to the repertory of the lute, long past its heyday but enjoying a final flowering in the German-speaking countries, represent, along with the works of S.L. Weiss, the culmination of the instrument’s 18th-century repertory. They require an instrument with 10 to 14 strings, but in Bach’s day were at least occasionally played on the lute-harpsichord, an instrument in whose construction Bach had assisted. The indistinct line between lute and harpsichord music is illustrated by the autograph of BWV 998, marked ‘pour La Luth ò Cembal’.

Many of Bach’s orchestral compositions must be presumed lost. The surviving repertory can in any case give only an incomplete idea of his output for larger instrumental ensembles, for he must have written many further works during his years at Köthen and while he was working with the collegium musicum in Leipzig. Traces of lost concerto movements may be found in numerous cantatas, such as BWV 42 (first movement), and other large-scale vocal works, such as the Easter Oratorio (first two movements); and various of the surviving harpsichord concertos, in particular, invite inferences about lost originals.

In the score bearing the dedication to Margrave Christian Ludwig of Brandenburg, the so-called Brandenburg Concertos are dated March 24, 1721. This is merely a terminus ante quem, for the concertos themselves must have been written over a considerable period before being assembled in 1721 as a collection of ‘Concerts avec plusieurs instruments’ (not as a single work in several parts). It cannot be proved that Bach composed instrumental music in his capacity as Konzertmeister in Weimar; but his position there and his preoccupation with the Italian concerto style during those years make it seem probable that he did. Of the Brandenburg Concertos, no.6 in particular points to the Weimar period, partly because of its indebtedness to the Italian type of concerto (above all in the middle movement) and also because of its unusual instrumentation (the particular combination of low strings is otherwise found only in Weimar cantatas). Other concertos (for instance the conjectural early version of no.1) may also belong to the Weimar period, but it is not possible to draw any firmer conclusion about a Weimar orchestral repertory.

The special significance of the Brandenburg Concertos resides in the fact that, like A. Vivaldi’s, they abandon the standard type of concerto grosso and use a variety of solo combinations. The originality of Bach’s ideas extends far beyond A. Vivaldi’s, as do the density of the compositional texture and the level of professional virtuosity. The devising of concise head-motifs, particularly in the first movements, shows a strong Italian influence. Most of Bach’s instrumentations are unprecedented. They feature all kinds of combinations, from homogeneous string sound (nos.3 and 6) to the heterogeneous mixing of brass, woodwind, string and keyboard instruments. Just as unusual is Bach’s conflation of the group concerto with the solo concerto in nos.2 and 5. No.5 probably represents the latest stage in composition of the set: it was written for the inauguration of the harpsichord he brought back from Berlin early in 1719 (an earlier version survives from about this date). At the same time it marks the beginnings of the keyboard concerto as a form.

For a long time Bach scholars assigned most of his chamber and ensemble music to the Köthen years. Recent studies based on original sources and style criticism have led to a thorough revision of the chronology affecting this part of his output. It now seems that only the smaller part of the instrumental ensemble music (or at least of what survives of it) belongs to the Köthen period, while the greater part was composed at Leipzig, and principally for the collegium musicum which Bach was associated with from 1723 and which he directed from 1729 to the early 1740s. Thus the four Orchestral Suites, with their leaning towards French style, were written in Leipzig: no.1 perhaps as early as 1725, nos.3 and 4 in about 1725 and after 1730 respectively and no.2 about 1739. The B minor Suite (no.2), with its hybrid mixture of concerto elements and suite form and the extraordinary virtuosity of its flute writing, is probably Bach’s very last orchestral work. The only solo concertos to survive in their original form from this time are the violin concertos in A minor and in E and the two-violin concerto in D minor, which again obviously relate to the collegium musicum. Pointers to lost works that may be supposed to have been composed in Köthen can be obtained from Leipzig pieces showing clear signs of reworking, above all cantata sinfonias with obbligato organ and the harpsichord concertos. Among the putative originals discernibin later recensions are concertos for oboe d’amore (after BWV 1053 and BWV 1055), for violin (after BWV 1052 and BWV 1060) and for three violins (after BWV 1064). The intended instrumentation of the original cannot always be conclusively determined from the later version, and allowance must also be made for substantial differences between the two versions, so that it is extremely rarely the case that reconstruction of a supposed but lost original is really possible. Bach never proceeded in a mechanical way; rather, he strove to give the arrangement an identity of its own by subjecting the model to further development and exhausting its potential. This often involved the addition of fresh contrapuntal parts, the alteration of detail and structural modification. Of special interest are Bach’s adaptations of instrumental works into vocal ones, such as the derivation of the first chorus of Cantata BWV 110 from BWV 1069; also of note is the wresting of the outer movements of an ensemble concerto (BWV 1044) out of the Prelude and Fugue in A minor for harpsichord (BWV 894).

The most noteworthy of the later concertos composed in the 1730s, with substantial changes to the originals on which they draw, are the Triple Concerto in A minor BWV 1044 (sharing several features with Brandenburg Concerto no.5), the seven harpsichord concertos BWV 1052-1058 and the concertos for two or more harpsichords bwv1060–65, all but one of them reworkings of earlier works by Bach himself (the exception is bwv1064, an arrangement of A. Vivaldi’s Concerto in B minor for four violins, op.3 no.10). In fact, Bach’s alterations and restructurings are sufficiently important – especially the deployment of the left hand of the harpsichord part and the invention of idiomatic harpsichord figuration – for works of this rank to be considered compositions in their own right. They owe their special historical importance to their occurrence at the beginning of the history of the keyboard concerto, a form which was to be taken up above all by Bach’s sons so that in Germany, until about 1750, it remained the exclusive preserve of the Bach family. A stimulus for the composition of the harpsichord concertos may have been the new instrument introduced on June 17, 1733 (‘a new harpsichord, the like of which no-one here has ever yet heard’), according to the announcement advertising the collegium musicum concert.

As with the orchestral music, a great many chamber compositions are thought to be lost. Once again the greatest losses affect the Köthen period, but the Weimar years also suffer. When the summary worklist in the obituary mentions ‘a quantity of other instrumental things, of every kind and for every kind of instrument’, it probably refers first and foremost to works for various chamber ensembles.

The unusual flexibility with which Bach manipulated the conventional genres of sonata and suite is comparable to his orchestral output, as regards formal and compositional aspects as much as textures. Particularly important is his emancipation of the harpsichord from its role as continuo instrument and its deployment as a true partner in the sonatas for harpsichord with violin (BWV 1014-1019), flute (BWV 1030-1033) and viola da gamba (BWV 1027-1029). The cycle of six harpsichord and violin sonatas (c1725-1726) were the first in a series of works with obbligato keyboard and paved the way for a new musical genre. The traditional trio sonata with continuo still cast its shadow (for example, in the opening movements of BWV 1015 and BWV 1019), but it yielded by stages to a more integrated three-part style (for example, the opening movements of BWV 1014 and BWV 1018). The only genuine trio sonatas to survive, apart from the one in the Musical Offering (BWV 1079), are BWV 1038 and 1039, dating from the 1730s. Bach’s arrangement of the gamba sonata BWV 1027, after BWV 1039 for two flutes and continuo is an illustration of the development of the new type of trio writing from the trio sonata. A similar procedure stood behind his earlier development of the organ sonata. Most movements of the organ sonatas are based on instrumental trios, as the arrangement of the first movement of bwv528 from a trio sonata movement for oboe d’amore, viola da gamba and continuo in Cantata BWV 76 illustrates. This same movement preserves a trace of the many lost trio sonatas of the Köthen years. Yet the trio sonatas of the Leipzig period, too, may represent only a small fraction of their original numbers, if the way the genre lingers on in the Musical Offering (BWV 1079) is any guide.

The list of surviving duo sonatas with continuo is also relatively short, and again dominated by works of the Leipzig period: the violin sonatas BWV 1021 and BWV 1023 and the flute sonatas BWV 1034-1035. The Fugue in G minor for violin and continuo BWV 1026, from before 1712, is not only Bach’s earliest surviving piece of ensemble music, it is also the only chamber-music piece of the pre-Köthen years to have survived as an independent entity. The only other sources we have for an idea of what kind of chamber music Bach wrote in his early years are the instrumental sonatas and sinfonias of the Weimar cantatas.

Bach’s creative powers in the Köthen years appear in a special light in the sonatas and partitas for solo violin, dating from 1720, and the suites for solo cello, which are probably earlier. The sonata for solo flute (BWV 1013) is not likely to have been composed in Köthen, for the playing technique is much more advanced than, for example, the writing for flute in Brandenburg Concerto No. 5 (BWV 1050). Yet all the works senza basso not only demonstrate Bach’s intimate knowledge of the typical idioms and performing techniques of each instrument, but also show his ability, even without an accompanying bass part, to bring into effective play dense counterpoint and refined harmony coupled with distinctive rhythms. The special importance of Bach’s chamber music was recognized at a very early date. J.F. Reichardt wrote in 1805, reviewing the first edition of the solo violin music, that the pieces represent ‘perhaps the greatest example in any art of the freedom and certainty with which a great master can move even when he is in chains’.

Bach’s preoccupation with the canon as the strictest form of counterpoint can be traced back to the Weimar period. In his organ chorales and particularly in the Orgel-Büchlein the canonic principle plays a major role. Canonic elements are present also in several of early vocal works. Here however it is a matter of canonic technique cropping up in a context of complex contrapuntal construction; as a genre in its own right, the canon, in Bach’s day, would appear almost exclusively as a theoretical example in composition teaching. It was in this sense that it was often favoured – generally in the form of a circular canon – by musicians for entries in students’ albums: such entries were normally notated in enigmatic fashion, setting the would-be solver an intellectual exercise. Bach wrote such canons in albums more than once; for the most part they are probably lost. Except for BWV 1076-1077, all the surviving individual canons (BWV 1072-1075, BWV 1078, BWV 1086) were probably dedicatory works of this kind; BWV 1077 was re-used for this purpose. What is probably the earliest of them is dated August 2, 1713 (BWV 1073, dedicatee uncertain); the latest is dated March 1, 1749 (bwv1078; dedicatee Benjamin Faber).

A new kind of theoretical canon came into being in connection with the Goldberg Variations (BWV 988), in which the canonic principle played a special part. In his personal copy of the Goldberg Variations (BWV 988) Bach wrote in 1747-1748 a series of 14 perpetual canons on the first eight bass notes of the aria ground (BWV 1087), exploring the most varied canonic possibilities of the subject, subsequently arranging the individual perpetual canons in a progressive order, organized according to their increasing contrapuntal complexity. The types included range from simple, double and triple canons, retrograde canons and stretto canons to a quadruple proportion canon by augmentation and diminution. Nos.11 and 13 of this series are identical with bwv1077 and 1076 (depicted on Haussmann’s Bach portrait of 1746).

Closely related to these (and likewise probably dating from the later 1740s) are the Vom Himmel hoch variations, where Bach first used a strictly canonic scheme for a monothematic work in several movements of progressive difficulty. The Musical Offering (BWV 1079) (1747) is also plainly influenced by this mode of musical thinking. Here, for a theme incomparably more complex than that of BWV 1087, he devised ten canons of differing structural types, notated as puzzle canons in the original printed edition of 1747. The series of canons on the ‘royal theme’ includes a canonic fugue, providing a bridge between the canons, which are primarily theoretical in conception though also intended for performance, and the two keyboard fugues or ricercares in three and six parts. A further constituent part of the Musical Offering (BWV 1079) is a trio sonata for flute, violin and continuo, also based on the royal theme. In its second slow movement Bach introduced echoes of the fashionable style practised at the Prussian court. The Musical Offering (BWV 1079), in effect a compendium in three sections, shows Bach elaborating on the theme supplied to him by Frederick the Great in every imaginable way for an ensemble of up to three instruments.

The Art of Fugue (BWV 1080) constitutes the final contribution to this group of monothematically conceived works intended as representative examples of a specific principle. As a didactic keyboard work, the Art of Fugue (BWV 1080) in some ways forms a counterpart to the two books of the ‘48’, with the difference that here it is exclusively the fugue that is in question, and, what is more, the fugues are developed from a single theme. Bach’s work on the Art of Fugue (BWV 1080) was accomplished in two stages – from about 1740 to about 1745, and then (in connection with preparing the work for publication) in about 1748-1750. The extant autograph score represents the conclusion of the first stage, in which the conception of the work already appears clearly: beginning with simple fugues (Bach avoided this term, speaking of ‘contrapunctus’), progressing through ‘counter-fugues’, double fugues and triple fugues, with interpolated canons, and culminating in a mirror fugue. For the printed version the number of movements was not only increased by four (two canons, a fourth simple fugue and most notably a closing quadruple fugue) but their order was rearranged so as to expound more logically the ‘chapter of instruction on fugues’. When Bach died the work may have been more ‘complete’ than it is in the form in which it has survived. In particular the quadruple fugue had surely been completed in all essentials, since the composition of its combinatorial section must necessarily be an early stage in the composition of a quadruple fugue. Only the three opening sections of the exposition, however, are extant, and these – further abbreviated by the editors, give the Art of Fugue (BWV 1080) the appearance of being a mighty torso.

The Musical Offering (BWV 1079) and the Art of Fugue (BWV 1080) mark both the end and the culmination of Bach’s activity as a keyboard composer in the broadest sense. While the two ricercars on the ‘royal theme’ of the Musical Offering (BWV 1079) represent different fugal styles (forward- and backward-looking) and different textures (three- and six-part polyphony), the Art of Fugue (BWV 1080) explores a notably more intensive monothematic conception. As a didactic keyboard composition in some sense it counterbalances the two parts of the ‘48’, yet with the difference that it concerns itself with fugue alone, in a series of compositions developed out of a single ‘principal composition’ (theme) – and does so using a technique in which forward- and backward-looking styles operate alongside each other, synoptically as it were. It was probably unintentional, and yet it is hardly by chance, that the initial premiss and the goal of Bach’s keyboard art and his musical thinking come together in the Art of Fugue (BWV 1080).

Bach’s methods of composition can be outlined only roughly: the sources, musical and literary, present no more than a fragmentary picture. ‘Methods’ here refers to Bach’s general procedures of composition, as far as these can be described objectively (without venturing into conjecture about creative psychology) and can be related to certain essential impulses and particularly characteristic approaches.

Bach’s vast knowledge of the musical repertory was a decisive factor behind his art. He had an intimate knowledge of the types and styles of composition of his time and in particular of the work of his most important contemporaries; moreover, he had a sound idea of the music of the past, extending back as far as G. Frescobaldi and G.P.d. Palestrina. The study of works by other masters went hand in hand with experimentation in his own. It is thus characteristic that his acquaintance with the works of D. Buxtehude and G. Böhm, with A. Vivaldi’s concer, with the Passions of R. Keiser and G.F. Handel and with the masses of A. Lotti and G.P.d. Palestrina should have left an immediate imprint on his compositions in the same genres. It was less a matter of imitation of a model than of an awareness of the possibilities, an expansion of his own manner of writing and a stimulation of his musical ideas. This is confirmed in a contemporary report by T.L. Pitschel on his manner of improvisation, according to which, before beginning his own fantasia, Bach as a rule played from music a work by another master (or perhaps one of his own) which would ignite his imagination. Further, C.P.E. Bach wrote that, in accompanying a trio, his father liked to extemporize a fourth part. This tendency to take compositions by others as a starting-point is paralleled in his late adaptations: in his arrangement of G.B. Pergolesi’s Stabat mater an obbligato viola part is added, replacing the one following the continuo in the original; and his version of the ‘Suscepit Israel’ from A. Caldara’s Magnificat in C expands it from a five-part into a seven-part piece. An important aspect of Bach’s procedure of composition is its systematic and encyclopedic nature. He habitually wrote works of one particular type within a relatively limited period: for example the Orgel-Büchlein, the ‘48’, the solo violin sonatas and partitas, the canons, the chorale cantatas etc. He was concerned to try out, to develop and to exhaust specific principles of composition. There are practically no completely isolated compositions. Relationships, correspondences and connections with other works can constantly be found. This approach to the procedure of composition is at once deep and yet of great natural simplicity; and it never results in mere repetition. Certainly there is repetition, of a kind, in the case of parodies or transcriptions of existing works. Yet even here it is inappropriate to speak of repetition, since in the process of parodying and transcribing, Bach always modified so that the end-product represents a fresh stage in the development of the original composition.

C.P.E. Bach related that his father did not actually compose at the keyboard – apart from some keyboard works whose material originated in improvisations – but that he often tried out his music on the keyboard afterwards. This procedure may be seen in the few instrumental works of which Bach’s autograph draft survives, for example the early versions of the Inventions in the Clavier-Büchlein for W.F. Bach, where an abundance of inserted corrections are to be found. In the vocal music, where a wealth of source material is available, the main stages of composition can often be reconstructed. In thematically and motivically self-contained movements, like arias and choruses, Bach normally began with the development and formulation of a motif, a phrase or a theme, which would be guided by the prosody of the text; he then added the contrapuntal voices, and continued in the same way, sometimes using ‘continuation sketches’ to plan the music’s progress in advance. In choral fugues he usually began by outlining the thematic entries, and wrote in the accompanying parts afterwards. The decisive step was the embarkation on the writing of a movement, for progress was in its essentials determined by established models (harmonic-tonal groundplan, modulation patterns, aria schemes) and governed by the principle of unified continuation (‘style d’une teneur’ and ‘Affekteinheitlichkeit’ – ensured by a unified motivic organization and interchange, permutation and transposition of component sections). The invention of the central idea was for Bach the critical moment in the process of composition, as the title-page of the Inventions specifies: ‘gute inventiones zu bekommen’ (‘how to achieve good inventions’); and this is borne out by C.P.E. Bach’s report that his first requirement of his composition pupils was the invention of ideas. With this the die was cast, down to a work’s emotional content. Outlines and sketches relating to this operation can sometimes be found in the original manuscripts; typically, however, Bach hardly required more than one or two attempts before arriving at the definitive form of his principal idea. The further elaboration of the idea – the dispositio, elaboratio anddecoratio – required mastery of his craft rather than inspiration.

In composing multi-movement vocal works Bach, understandably, began as a rule with the self-contained movements and only afterwards worked at the recitatives and chorales. In the recitatives he normally first wrote out the text and then added the melody and bass, section by section. In the chorales the bass was added to the melody and the middle parts were inserted later. Then all the movements were revised in detail, and sometimes corrections were made. The appearance of Bach’s working drafts is thus unusually clear and neat as a whole, although it is mainly in his fair copies that the particular quality of his handwriting, a quality comparable to that of his music, is expressed. The physical state of the fair copy had to reflect the degree of artistic perfection to which the composer aspired, and the pains taken to achieve neatness and clarity in the copy are not evidence of pedantry. Rather, Bach was aware of the dichotomy between the perfection of the musical idea and that of its representation in performance. For this reason and no other he made the following statement in 1738, through the mouth of his spokesman J.A. Birnbaum: ‘One does not judge a composition first and foremost by the impression of its performance. Yet if such judgment, which can be deceptive, is not to be taken into consideration, then I see no other way of forming an opinion about it except by looking at the work as it is set down in notation.’

Ultimately, for Bach, the process of composition was an unending one. Dynamic markings and indications of articulation would be inserted as he looked through the parts; he would revise and improve a work when he was copying it out, and when giving further performances would make fresh alterations and improvements. He also inserted corrections in works already in print. Throughout his life Bach was his own severest critic. Even in works which went through two or three different versions, like the chorale prelude An Wasserflüssen Babylon bwv653, the ‘final’ version does not represent a definitive one but merely a further stage in the search for perfection – the central and ultimate concern of Bach’s method of composition.